Health and economic benefit of China's greenhouse gas mitigation by 2050

As the biggest greenhouse gases (GHGs) emitter, China's climate mitigation has tremendous contributions to the global carbon and air pollutants reductions. This study is trying to extract the co-benefit on air quality, public health and economic costs in China and worldwide from China's GHGs mitigation policy. We construct two scenarios, with moderate climate mitigation action worldwide, versus more stringent climate mitigation action in China. We use the GAINS model to predict the GHGs and air pollutants emissions in the two scenarios, and a state-of-the-art global chemical transport model to simulate the annual PM(2.5)concentrations. We then use IMED|HEL, which is a health assessment model, to estimate the health impacts and economic cost of PM(2.5)pollution in each country. Results show China's mitigation has significant impact on both air quality and health improvement in eastern China and eastern Asia, a little bit impact in the rest of Asia. The improved air quality could avoid 0.37 million premature deaths due to ambient PM(2.5)exposure by 2050s globally, with the majority happening in China. We use the willingness to pay method to estimate the economic benefits from the improved air quailty, and find that the reduced ambient PM(2.5)concentration could avoid $406 billion and $1206 billion economic costs by 2030s and 2050s globally, with China the largest fraction of 98.5% ($400 billion) and 99.5% ($1200 billion), respectively. The reduced ambient PM(2.5)exposure can also avoid 11.3 million cases morbidity globally by 2050s, due to asthma attacks and hospital admissions. Our study shows most of the economic benefits from air quality improvement due to China's mitigation happens in China, followed by the eastern Asia (such as South Korea and Japan) and the rest of Asia. Health improvement is the main fraction of the potential benefits, such as saving health expenditure, increasing the work time.